Diversification of Amidyl Radical Intermediates Derived from C–H Aminopyridylation

C–H amination chemistry promises to streamline access to nitrogen-containing fine chemicals. The typical need for N-activating substituents — such of N-sulfonyl groups, which are challenging to remove and difficult to engage in synthetic elaboration — limits synthetic utility. Here, we demonstrate that N-benzylaminopyridinium species, generated by C–H aminopyridylation, provide a platform for synthetic elaboration via reductive N–N bond activation to unveil electrophilic N-centered radicals. These reactive intermediates can be trapped either via anti-Markovnikov olefin carboamination to provide access to tetrahydroisoquinolines, which are important heterocycles in molecular therapeutics, or via aza-Rubottom chemistry with silyl enol ethers to provide alpha-amino ketones. This approach broadens the synthetic utility of N-alkylaminopyridinium intermediates and demonstrates a new approach to C–H amination with synthetically addressable, bifunctional reagents.